Three days after rebels and the Syrian army agreed a truce at Babbila near Damascus, jihadists said they rejected the deal and hauled down and trampled on Syria's flag Thursday.

The Syrian Observatory for Human Rights said fighters from the Islamic State of Iraq and the Levant (ISIL) -- the most radical group in Syria's revolt -- "announced their rejection of any armistice" with the authorities.

At least six people were killed when a car bomb exploded at a border crossing between Syria and Turkey on Thursday, a Turkish official told Agence France Presse.

The official said the bomb detonated on the Syrian side of the Bab al-Salama crossing, adding that 45 people were wounded.

Syrian rebels were engaged in fierce battles Thursday with regime forces trying to capture the town of Yabrud, their last stronghold in the strategic Qalamun region near the Lebanese border, an NGO said.

Meanwhile, in the northern city of Aleppo, eight soldiers were killed by a rebel suicide bombing at the city's central prison, which rebels have long been trying to capture, the Syrian Observatory for Human Rights said.

A Syrian court has sentenced two men to prison for giving "false testimony" implicating Damascus in the assassination of former prime minister Rafik Hariri, a Syrian newspaper said Thursday.

The Al-Watan newspaper, which is close to the government, said a court on Wednesday sentenced Murad Akram to 10 years in prison, including five years with hard labor, and Zuhair Mohamed Saeed Siddiq to 20 years in prison with 10 years of hard labor.

The U.N. agency for Palestinian refugees UNRWA has resumed distribution of aid at the besieged Yarmuk camp in southern Damascus, a spokesman said Thursday.

Distribution of desperately needed food and medicine was halted on February 8 after clashes broke out, but resumed Wednesday, Chris Gunness said.

Russian Foreign Minister Sergei Lavrov visited Baghdad on Thursday for talks with senior Iraqi officials, including Prime Minister Nouri al-Maliki, that focused on weapons sales and Syria.

The visit, which follows a meeting between Russian President Vladimir Putin and Egyptian army chief Abdel Fattah al-Sisi last week, may point to increased efforts by Moscow to expand ties with Middle Eastern countries with which Washington has had close relations.

Syrian media on Thursday accused Jordan of trying to stir up the rebel front in the south of the country with support from the United States and Saudi Arabia.

"The southern front is today the most prominent after the subject was widely discussed under the aegis of the palace in Jordan," the Al-Thawra government daily wrote.

Western countries presented the U.N. Security Council late Wednesday with a draft resolution on humanitarian aid for Syria but Russia so far does not back it, raising the risk of a veto.

The vote on the draft, which involved intense negotiations with Russia, Syria's main ally, is expected Friday.

Denmark's premier, whose country is a key player in an international operation to destroy Syria's chemical arsenal, said Wednesday she was "cautiously optimistic" the timetable for doing so will be met.

Helle Thorning-Schmidt was speaking during a meeting with Cypriot President Nicos Anastasiades aboard the Danish frigate HDMS Esbern Snare, which is escorting Syrian chemical weapons shipments and is operating out of nearby Cyprus.

U.S. Secretary of State John Kerry met Wednesday with Palestinian president Mahmoud Abbas as he seeks progress in his quest for a Middle East peace deal.

The top U.S. diplomat has spent months trying to get the Israelis and the Palestinians to agree on a framework for resolving their decades-old conflict, but the negotiations have shown little sign of progress, with each side blaming the other.